This invention relates to a cushioning device for a mattress, sofa, seat or the like wherein partial support is obtained from a fluid, such as air. In some embodiments, this invention relates to a combination of a resilient member, and an impervious envelope having intake and exhaust valves which make up a deformable and reformable cushion.
In the prior art it is known to use "air-sacks", "bladders" or "air cells", as they have been called, as a support means for a mattress, e.g. U.S. Pat. No. 201,728 granted to White on Mar. 26, 1878 and U.S. Pat. No. 4,477,935 granted to Griffen on Oct. 23, 1984. It is also known to provide a means and method of controlling the amount of inflation in such air cells to support a person at a predetermined height to optimize comfort or support. For example, U.S. Pat. No. 4,989,283 teaches the use of a microprocessor to monitor and to control pressure in a plurality of air cells of a mattress to provide different support characteristics for different positions of a person on the mattress. U.S. Pat. No. 5,070,560 provides a mattress structure in which air cells have a valve for manually inflating or deflating individual air cells to desired pressures to relieve bed sores.